1. Field of the Invention
The present invention relates to a touch device, especially to an electrode structure of the touch panel, the method thereof and the touch panel.
2. Description of the Related Art
The touch panels have been widely used in various electronic devices in recent years. These can even replace the conventional keyboards and mice to control the electronic devices.
The conventional touch panel includes an active area placed on a substrate. The active area is usually covered with transparent conductive film. When the fingers or stylus touch the active area, the touch signals are created for the subsequent processes.
There are many types of touch sensing methods, such as resistive sensing type, capacitive sensing type, acoustic wave sensing type, optical sensing type and the like. For the capacitive sensing method, the touch panel perceives touch locations by detecting the change in capacitance due to the proximity of conductive objects such as metals or fingers. The capacitive touch panel is widely adopted because of the advantages like high rigidity, accuracy and longevity, accurate response time, operating temperature and initializing force.
Various types of touch panels with different electrode patterns are newly developed for detecting the touch locations of the fingers or conductive objects on the touch surface. For example, U.S. Pat. No. 6,970,160 disclosed a lattice touch-sensing system for detecting a position of a touch on a touch-sensitive surface. The lattice touch-sensing system may include two capacitive sensing layers, separated by an insulating material, where each layer consists of substantially parallel conducting elements, and the conducting elements of the two sensing layers are substantially orthogonal to each other. Each element may comprises a series of diamond shaped patches that are connected together with narrow conductive rectangular strips. Each conducting element of a given sensing layer is electrically connected at one or both ends to a lead line of a corresponding set of lead lines. A control circuit may also be included to provide an excitation signal to both sets of conducting elements through the corresponding sets of lead lines, to receive sensing signals generated by sensor elements when a touch on the surface occurs, and to determine a position of the touch from the sensing signals.
Although a series of diamond shaped patches of the touch-sensing system are disclosed in above-mentioned patent, the lattice touch-sensing system includes two capacitive sensing layers, separated by an insulating material. Thus, the lattice touch-sensing system is too thick to meet the requirement of reducing the thickness of the capacitive touch panel. Besides, the conventional capacitive touch panel is manufactured by forming the two capacitive sensing layers on the two sides of a substrate and connecting each series of diamond shaped patches with lead lines through the holes on the substrate. Therefore, the manufacturing process is complicated.